Supplied air hoods are used for respiratory protection and to keep the worker""s face, head and hair free from contamination. They may also reduce the risk of skin absorption of chemicals. Many times, hoods are the only viable devices to provide protection for workers with beards, long sideburns, small faces, or other features that may increase the difficulty of achieving a proper seal with other types of respirators.
A hood covers the wearer""s head and neck and drapes onto the shoulders. The portion that drapes onto the shoulders is called a shroud. An inner shroud, that is tucked into the wearer""s shirt or garment, may also be provided. The hood itself does not provide head impact protection. Air is typically supplied to the interior of the hood at the front or back via a hose. Supplied air hoods are available from many manufacturers, for example, Minnesota Mining and Manufacturing Company, St. Paul, Minn. (hereinafter referred to as xe2x80x9c3Mxe2x80x9d); E.D. Bullard Company, Cynthiana, Ky.; Dalloz Safety, Reading, Pa.; and North Safety Equipment, Cranston, R.I.
Hoods typically are made from a non-woven material having a polymeric coating on the surface; one example of such a commercially available material is TYVEC QCr(trademark). Hoods can also be made from paper, polymeric film or cloth. Preferably, the hood material is impervious to air or liquid flow through the material.
A transparent plastic lens is attached to the hood material. The lens is designed to provide protection against splash hazards, as well provide the wearer with a field of vision. The lens also is designed to retain the supplied air within the hood.
A hood is generally used in combination with headgear, either a head suspension or a hardcap. The head suspension or hardcap is used to support the hood on the wearer""s head and to provide at least a minimal space between the wearer""s face and the plastic lens. The plastic lens is typically secured to an extending brim of the hardcap or to an extending shield or lens mount band on the head suspension. The hood is attached to the headgear typically in a detachable manner.
A hardcap is used with a hood when impact protection for the head is needed, for example, from overhead obstructions or potentially falling objects. A hardcap can be similar to a construction worker""s hardhat.
In many work environments, the impact protection provided by the hardcap is not needed; thus a head suspension is used with the hood instead. A head suspension is basically a flexible frame that fits onto the wearer""s head and includes an extended mount band that supports the hood and provides some distance between the lens and the wearer""s face.
Wearers of hoods with head suspensions have encountered problems caused by the outer shroud. In some instances when a wearer turns his head, the hood does not move in conjunction with the head. Instead, the head turns and the hood does not follow because of the weight of the shroud holding the hood back, thereby impairing the wearer""s side vision. In addition, the lens may collapse onto the wearer""s face when the wearer attempts to turn his head.
In view of the above, there is a need for a head suspension design that securely fixes the position of the plastic lens in relation to the wearer""s field of vision and prevents the lens from collapsing toward the wearer""s face. This invention affords an improved head suspension with enhanced lens stability.
In one embodiment of the present invention, a head suspension, for use with a hood and for suspending a transparent lens therefrom is provided. The head suspension comprises a headband and a lens mount, the lens mount for mounting the lens to the head suspension. The lens mount is extended from the headband and is attached to the headband by at least two nonparallel braces that bridge the area from the headband to the lens mount. In a preferred embodiment, the lens mount is attached to the headband in at least four points via two braces and two mounting points.
The braces provide increased lateral support for the hood and lens and are positioned between the headband and the lens mount so that they are nonparallel to each other. Preferably, the braces are positioned at an angle less than 90xc2x0 in relation to the headband so that the braces diverge as they extend from the headband to the lens mount. The braces may be individual pieces that are assembled together with the headband and lens mount. Alternatively, the braces may be formed integral with the headband or integral with the lens mount.
These and other advantages and features that characterize the invention are illustrated below in the detailed description and accompanying drawing.